My current intake is a 4150 flange FRPP G429 which is really an Edelbrock Victor.

The 4150 Victor and the 4500 Victor are the exact same manifold save for the carb pad machining. Some guys open the 4150 up to 4500 size (and redrill the carb stud holes) instead of buying a new manifold and that is what I have planned to do. However, I see lots of people running adapters with great success so that brings me to the question: Is there ever an advantage to just using a 4150/4500 adapter?

I run an adapter on a 4150 flange and was told by several ppl that that was the way to go as I had originally thought about welding and machining that intake to bolt the Dominator directly to it.

I will say too that I did machine the crap out of that thing back a year or so ago and did pick up some performance from it. Right now I only have about a quarter inch of the original 4150 flange left as I took about 3/4" out of it in both directions, ie, fore and aft and side to side. Here's the before and after pics.

I'm really going back and forth on this. Mainly because the current setup fits under the stock hood and stock '83 hood scoop (barely).

I have pretty much resolved to the fact a cowl hood or some kind of forward facing scoop will need to be used, but I don't want it to get to ridiculous. I like the stealthy look of the car (it lives in my driveway) and don't want to screw that up too much, but ultimately going faster trumps mundane looks. haha

I was under the impression the SV 4500 had bigger ports than the 4150 version, but don't know for sure.

I have always liked a Dominator on an adapter to a 4150 intake. I do a lot of massaging to make it a nice smooth transition. I've run them on my own engines and on engines I've built. They work good that way IMO.

I decided to just go ahead and modify the intake to accept a 4500. That way I can still play with different sized spacers, etc if I want.

4500 gasket on the 4150 flange.

Sharpie'd an outline around the gasket.

Drilled holes along the lines I wanted to cut and took a ball peen and tapped the big chunks out. The casting is really thin where the clovers are because this intake is available in both flanges. If I were doing it again, I'd drill smaller holes along the perimeter so I would have less material to remove with the carbide. I matched my clover walls to the existing casting walls inside. The photos make the clovers look a little wonky, but they look good in person. lol

I countersunk the alumimum screws, then drilled and tapped the new stud holes. The new holes actually go through the heads of the filler screws. Didn't grab a pic of that for some reason.

Finished. I also drilled and tapped a vacuum port in the back because this manifold did not have a vacuum port.

Intake gaskets will be here today and I maybe I can find some time soon to button it all back up.

James,I did the same thing. Charlie Evans who did my cylinder heads told me that the dominator maniold has a better transition from the carb to the plenumn/runners.So I went down the path off converting to a Dominator.I didn't go any faster from my 1000 hp 4150 untill I straightened out the fuel curve in the Dominator (2 circuit).Now ther car is faster and seems to be repeating, something it never did before.So you will be happy.Cheers Colin